This invention relates to the field of dual-band radios, and, more specifically, to the integration of components of dual-band transceivers.
In the current market for wireless telephones (also called mobile phones, cell phones, mobile stations, etc.), there is a strong desire to reduce size and cost of the wireless telephone while simultaneously improving performance. One approach to reducing the size and cost of the wireless telephone is to increase the level of component integration. In the current art, however, the receiver front end (including a low noise amplifier) and transmitter power amplifiers have not been integrated because the transmitter""s power amplifier may generate interference at the receiver. The integration of the transmitter and receiver amplifiers has not been achieved despite the fact that there are advantages for having the low-noise receiver amplifier built on the same substrate as the transmitter power amplifier to optimize the common characteristics.
In accordance with one aspect of this invention, a transceiver front end is provided that selectively transmits and receives on either of a first frequency and a second frequency wherein the front end comprises an integrated circuit having a power amplifier configured to amplify signals for transmission on a first frequency and a low-noise amplifier configured to amplify signals received on the second frequency.
In accordance with another aspect of this invention, the transceiver further includes a local oscillator and the integrated circuit includes a down-converter connected to the low-noise amplifier and the local oscillator that converts a signal on the second frequency to an intermediate frequency.
In accordance with a further aspect of this invention, the integrated circuit is a first integrated circuit and the transceiver further includes a second integrated circuit having a power amplifier configured to amplify signals for transmission on the second frequency and a low-noise amplifier configured to amplify signals received on the first frequency. The second integrated circuit may also include a second down-converter connected to the low-noise amplifier and the local oscillator. Further, either or both of the first and second integrated circuits may include a substrate of gallium arsenide (GaAs). The first frequency and the second frequency may be different frequencies.
In accordance with another aspect of this invention, a transceiver that selectively transmits and receives on either the first frequency and the second frequency band is disclosed wherein the radio has a multi-stage first frequency band transmitter, a multi-stage first frequency band receiver, a multi-stage second frequency band transmitter, and a multi-stage second frequency band receiver. The transceiver includes a first substrate having one or more stages of the multi-stage first frequency band transmitter and one or more stages of the second multi-frequency band receiver and a second substrate having one or more stages of the multi-stage second frequency band transmitter and one or more stages of the multi-stage first frequency band receiver. Further, a first of the stages of the multi-stage first frequency transmitter comprises a power amplifier and the one or more stages of the multi-stage first frequency band transmitter comprises the power amplifier. Additionally, the first of the stages of the multi-stage second frequency transmitters comprises a power amplifier and one or more of the stages of the multi-stage second frequency band transmitter on the first substrate comprise a power amplifier. Further, both the first frequency and the second frequency receivers may include a mixer.
In accordance with another aspect of this invention, a process for fabricating a dual-band transceiver front end is disclosed, wherein the transceiver has a multi-stage first frequency transmitter, a multi-stage first frequency receiver, a multi-stage second frequency transmitter and a multi-stage second frequency receiver. The process includes providing a substrate, fabricating one or more stages of the multi-stage first frequency transmitter on the substrate and fabricating one or more stages of the multi-stage second frequency receiver on the same substrate. Fabricating one or more of the stages of the first frequency transmitter may comprise fabricating a power amplifier on the substrate and fabricating one or more stages of a multi-stage second frequency receiver comprises fabricating a low-noise amplifier on the substrate. The process may further include fabricating a down-converter on the substrate connected to the low-noise amplifier.
In accordance with a further aspect of this invention, the substrate may be a first substrate and the process further includes providing a second substrate, fabricating one or more stages of multiple stage second frequency transmitter on the second substrate and fabricating one or more stages of the multi-stage first frequency receiver on the substrate. The steps of fabricating on this second substrate may include fabricating a power amplifier, fabricating a low-noise amplifier and fabricating a down-converter.